Device and method for controlling actuating devices for the active suspension of vehicles, in particular trains

ABSTRACT

The present invention relates to a control method and control apparatus for controlling actuator apparatus implemented in active suspension apparatus for vehicles, in particular rail vehicles, said control method and said control apparatus being characterized in that they use the articulated architecture of the train to derive the local curvature of the track in real time, in which control method and control apparatus the control signal transmitted by said control apparatus to the actuator apparatus of the bogie of order n in the articulated train is a function of measurements of at least one deflection angle α i  at an articulation center situated between adjacent carriages and of the position offset h j  of said articulation center relative to the track.

BACKGROUND OF THE INVENTION

The present invention relates generally to relationships for controllingactive suspension apparatus for vehicles, in particular rail vehicles,and more particularly to a method and apparatus for controlling actuatorapparatus for active suspension of vehicles, in particular railvehicles.

The following description relates to actuator apparatuses implemented inprior art active suspensions for rail vehicles.

Such actuator apparatuses, e.g. hydraulic, pneumatic, or electricactuators, are associated with transverse or vertical secondarysuspension systems on rail vehicles to obtain a more comfortable ride.

A first prior art solution, implemented by Fiat in tilting trainsETR450, ETR460, and ETR470 now in commercial service, is characterizedby the use of pneumatic actuators acting in parallel with the secondarysuspension to as to perform body-bogie re-centering on curves taken atvery high speed.

This re-centering is necessary because of the architecture of the Fiattilting bogie in which the tiltable bolster (i.e. cross-member) issituated above the secondary suspension.

Another prior art solution is implemented by SGP from the Siemens Group,and was presented at the 28^(th) “Moderne Schienenfahrzeuge” railconference in Graz, Austria, in October 1993.

That solution includes apparatus having actuators which may be pneumaticand which are disposed in parallel with the secondary suspension.

In such a solution, the control signal for controlling the actuator isessentially a function of the transverse offset between the body and thebogie as measured by a sensor.

Another prior art solution is implemented by Hitachi in the Shihkansen400 and is described in the article published in the October 1992edition of “Japanese Railway Engineering”.

In addition, Hitachi's Document JP 8 048 243 which is applicable to theWIN350 prototype train describes implementing pneumatic or hydraulicactuators in parallel with the secondary suspension.

That prior art solution uses inertial sensors of the accelerometer typein the vehicle body.

The object of that document is to reduce vibration level to within anarrow frequency band.

Such vibration characterizes sustained yaw motion of the carriages.

Another prior art solution is implemented by Faiveley.

Documents FR 2 689 475 and FR 2 689 476 relate to that solution.

A prototype vehicle based on a main-line passenger car or “carriage”uses pneumatic cushions disposed horizontally between the body and thebogies and acting transversely.

The cushions are controlled so as to regulate the transverse position ofthe body relative to the bogie about a zero position.

Such regulation is however akin to servo-controlling position.

In such a solution, the control signals are generated on the basis of asingle sensor for sensing transverse displacement between the body andthe bogie.

From the actuator apparatus implemented in prior art active suspensionapparatus on rail vehicles, it can be seen that it is known thatactuator apparatuses can be disposed in parallel with the secondarysuspensions of rail vehicles.

In addition, two modes of control are envisaged: a first mode consistsin using the actuator under conditions in which position isservo-controlled, and a second mode consists in using the actuator underconditions in which force is servo-controlled.

From actuator apparatus implemented in prior art active suspensionapparatus on rail vehicles, it can be seen that the most commonly usedsensors are of the inertia type (accelerometers) and of the inductivetype (measuring relative displacement and relative velocity, between twomoving bodies).

SUMMARY OF THE INVENTION

An object of the invention is thus to improve the smoothness of the rideexperienced by the passengers in articulated trains of vehicles, inparticular of the very high speed train type, so as to enable suchtrains to operate at speeds higher than 350 km per hour while retainingthe level of comfort currently observed on trains running at 300 km perhour.

This improvement must be obtained without providing additional apparatusrelating to the track, e.g. apparatus for pre-recording track curves,smart beacons, etc.

The merit of the Applicant is to teach the use of a particulararticulated train architecture to derive information that cannot beobtained by using known sensors and that can be used to control actuatorapparatus.

In other words, the present invention consists in taking advantage ofthe articulated train architecture currently implemented in theApplicant's very high speed trains and in enabling the articulated trainto be used as a track inspection vehicle to derive the local curvatureof the track in real time.

According to the invention, the control apparatus for controllingactuator apparatus implemented in active suspension apparatus forvehicles, in particular rail vehicles, is characterized in that it usesthe articulated architecture of the train to derive the local curvatureof the track in real time.

The control apparatus of the invention for controlling actuatorapparatus implemented in active suspension for vehicles also satisfiesat least one of the following characteristics:

the control signal transmitted by said control apparatus to the actuatorapparatus of the bogie of order n in the articulated train is a functionof measurements of at least one deflection angle α_(i) at anarticulation center situated between adjacent carriages and of theposition offset h_(j) of said articulation center relative to the track;

said actuator apparatus is force servo-controlled, said actuatorapparatus setting the force applied to a vehicle body of an articulatedtrain of vehicles from a bogie n associated with said body, said controlapparatus delivering a general control signal, signal_(n), for bogie n,that is a function of an intermediate parameter δ_(n) that is a functionof at least one deflection angle α_(i) and of at least one positionoffset h_(j) of said articulation centers relative to the track;

said intermediate parameter δ_(n) for n>2 is given by the followingformula:

δ_(n)=α_(n)/2+α_(n+1)+(3·h _(n+1)−2·h _(n+2) −h _(n−1))/(2·d)

 where:

d is the distance between two articulation centers in the lengthdirection;

α_(n) is the deflection angle of the articulation center at the bogie n;and

h_(n) is the position offset of the articulation center of the bogie nrelative to the track;

for the second (n=2) bogie of the train, δ₂ is given by the followingformula:

δ₂=α₂/2+(2·h ₂ −h ₃ −h ₁)/(2·d)

and for the first (n=1) bogie of the train, δ₁=0; and

said general control signal signal_(n) for bogie n is given by thefollowing formula: $\begin{matrix}{{signal}_{n} = \quad {{{Gain1} \cdot \left( {V_{TMn} - V_{TVn}} \right)} + \left( {V_{x} \cdot \delta_{n}} \right)}} \\{= \quad {{Gain1} \cdot \left( {{{{/{t}}}\quad \left( h_{n} \right)} + {V_{x} \cdot \delta_{n}}} \right)}}\end{matrix}$

 where:

V_(TMn) represents the transverse velocity of a point M belonging to thevehicle body and located at the articulation center;

V_(Tvn) represents the transverse velocity of the point belonging to thetrack that, in the horizontal plane and when the train is stationary,coincides with the point M; and

V_(x) represents the velocity at which the train is advancing.

According to the invention, the method of controlling actuator apparatusimplemented in active suspension apparatus for vehicles, in particularrail vehicles, is characterized in that it includes a step consisting inusing the articulated architecture of the train to derive the localcurvature of the track in real time.

The method of the invention for controlling actuator apparatusimplemented in active suspension for vehicles also satisfies at leastone of the following characteristics:

said control signal transmitted by said control apparatus to theactuator apparatus of the bogie of order n in the articulated train is afunction of measurements of at least one deflection angle α_(i) at anarticulation center situated between adjacent carriages and of theposition offset h_(j) of said articulation center relative to the track;

said actuator apparatus is force servo-controlled, said actuatorapparatus setting the force applied to a vehicle body of an articulatedtrain of vehicles from a bogie n associated with said body, said methodincluding a step consisting in delivering a general control signal,signal_(n), for bogie n, that is a function of an intermediate parameterδ_(n) that is a function of at least one deflection angle α_(i) and ofat least one position offset h_(j) of said articulation centers relativeto the track;

said intermediate parameter δ_(n) for n>2 is given by the followingformula:

δ_(n)=α_(n)/2+α_(n+1)+(3·h _(n+1)−2·h _(n+2) −h _(n−1))/(2·d)

 where:

d is the distance between two articulation centers in the lengthdirection;

α_(n) is the deflection angle of the articulation center at the bogie n;and

h_(n) is the position offset of the articulation center of the bogie nrelative to the track;

for the second (n=2) bogie of the train, δ2 is given by the followingformula:

δ₂=α₂/2+(2·h ₂ −h ₃ −h ₁)/(2·d)

and for the first (n=1) bogie of the train, δ₁=0; and

said general control signal signal_(n) for bogie n is given by thefollowing formula: $\begin{matrix}{{signal}_{n} = \quad {{{Gain1} \cdot \left( {V_{TMn} - V_{TVn}} \right)} + \left( {V_{x} \cdot \delta_{n}} \right)}} \\{= \quad {{Gain1} \cdot \left( {{{{/{t}}}\quad \left( h_{n} \right)} + {V_{x} \cdot \delta_{n}}} \right)}}\end{matrix}$

 where:

V_(TMn) represents the transverse velocity of a point M belonging to thevehicle body and located at the articulation center;

V_(Tvn) represents the transverse velocity of the point belonging to thetrack that, in the horizontal plane and when the train is stationary,coincides with the point M; and

V_(x) represents the velocity at which the train is advancing.

One advantage of the method and apparatus of the invention forcontrolling a force servo-controlled actuator is that performance isincreased without requiring any increase in the numbers of sensors, ofprocessing apparatuses, or of actuator apparatuses.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, characteristics, and advantages of the invention appearon reading the following description of a preferred implementation ofthe method and apparatus for controlling a force servo-controlledactuator given with reference too the accompanying drawings, in which:

FIG. 1 shows a preferred method of the invention for deriving trackcurvature; and

FIG. 2 shows the relative performance, in terms of comfort, for activetransverse suspension apparatus achieved by implementing the method ofthe invention for deriving track curvature (curve F) in comparison withthe performance obtained by prior art methods (curves C and D).

DETAILED DESCRIPTION OF THE INVENTION

According to an essential characteristic of the invention, the controlapparatus for controlling actuator apparatus implemented in activesuspension apparatus for vehicles, in particular rail vehicles, uses thearticulated architecture of the train to derive the local curvature ofthe track in real time.

For this purpose, the control signal transmitted by the controlapparatus to the actuator apparatus of the bogie of order n in thearticulated train is a function of measurements of a certain number ofdeflection angles at the articulation centers situated between adjacentcarriages, and of the position offsets of the articulation centersrelative to the track.

The combined use of measurements of at least one deflection angle α_(i)at an articulation center situated between adjacent carriages and of theposition offset h_(j) of said articulation center relative to the trackupstream and downstream from the bogie n makes it possible to derive thelocal curvature of the track at the bogie n.

The method and apparatus of the invention for controlling actuatorapparatus implemented in active suspension apparatus for vehicles, inparticular rail vehicles, uses the articulated architecture of the trainto derive the local curvature of the track in real time.

The control signal transmitted by the control apparatus to the actuatorapparatus of the bogie of order n in the articulated train is a functionof measurements of at least one deflection angle α_(i) at anarticulation center situated between adjacent carriages and of theposition offset h_(j) of said articulation center relative to the track.

The actuator apparatus is force servo-controlled.

The actuator apparatus sets the force applied to a vehicle body of anarticulated train of vehicles from a bogie n associated with the body,the control apparatus delivering a general control signal, signal_(n),for bogie n, that is a function of an intermediate parameter δ_(n) thatis a function of at least one deflection angle α_(i) and of at least oneposition offset h_(j) of the articulation centers relative to the track.

The intermediate parameter δ_(n) for n>2 is preferably given by thefollowing formula:

δ_(n)=α_(n)/2+α_(n+1)+(3·h _(n+1)−2·h _(n+2) −h _(n−1))/(2·d)

where:

d is the distance between two articulation centers in the lengthdirection;

α_(n) is the deflection angle of the articulation center at the bogie n;and

h_(n) is the position offset of the articulation center of the bogie nrelative to the track;

for the second bogie of the train (n=2), δ2 is given by the followingformula:

δ₂=α₂/2+(2·h ₂ −h ₃ −h ₁)/(2·d)

and for the first bogie of the train (n=1), δ₁=0.

Simulation trials have made it possible to determine a general controlsignal in the following form:

signal_(n)=Gain1·(V _(TMn) −V _(TVn+Δs))

where:

V_(TMn) represents the transverse velocity of a point M belonging to thevehicle body and located at the articulation center; V_(TMn) isgenerally obtained by integrating the transverse acceleration at thesame point over time;

V_(TVn)+Δs represents the transverse velocity of the track at a distanceΔs ahead of the bogie of order n; and

Gain1 is an adjustment parameter.

Means proposed to estimate the velocity V_(Tvn+Δs) are given by thefollowing formula:

V_(Tvn+Δs)=V_(TVn)+δ_(n)·V_(x)

where:

V_(Tvn) represents the transverse velocity of the point belonging to thetrack that, in the horizontal plane and when the train is stationary,coincides with the above-mentioned point M; and

V_(x) represents the velocity at which the train is advancing.

The general control signal signal_(n) is then obtained for bogie n,which signal is given by the following formula: $\begin{matrix}{{signal}_{n} = \quad {{{Gain1} \cdot \left( {V_{TMn} - V_{TVn}} \right)} + \left( {V_{x} \cdot \delta_{n}} \right)}} \\{= \quad {{Gain1} \cdot \left( {{{{/{t}}}\quad \left( h_{n} \right)} + {V_{x} \cdot \delta_{n}}} \right)}}\end{matrix}$

FIG. 1 shows a preferred method of the invention for deriving trackcurvature.

As shown in FIG. 1 which shows the four articulation centerscorresponding to the bogies B of ranks n−1 to n+2 in the articulatedtrain, as well as the four points V_(n) of the track V having the sameabscissa values, the magnitude to be measured is the angle δ_(n) betweenthe chords interconnecting the points of the track (V_(n−1)-V_(n+1)) and(V_(n+1)-V_(n+2)), the respective directions of which are treated asbeing the tangents to the curve at V_(n) and in the middle of thesegment (V_(n+1)-V_(n+2)).

The transverse distances between the articulation centers and thecorresponding points of the track are assumed to be known by thesensors, as are the relative yaw angles α_(n) and α_(n+1) of the vehiclebodies. It is then easy to compute the angle δ_(n) to a first order asdefined above.

FIG. 2 shows the relative performance, in terms of comfort, for activetransverse suspension apparatus achieved by implementing the method ofthe invention for deriving track curvature (curve F) in comparison withthe performance obtained by prior art methods (curves C and D).

What is claimed is:
 1. A control apparatus for controlling an actuatorapparatus implemented in a suspension system of a vehicle, the vehiclecomprising bodies articulated together and traveling on a track, thecontrol apparatus comprising: first means for accessing an articulatedarchitecture of the vehicle; second means for deriving a local curvatureof the track in real time based on the articulated architecture of thevehicle; and third means for delivering a control signal to the actuatorapparatus to control the suspension system of the vehicle based on thelocal curvature of the track derived by the second means.
 2. Apparatusaccording to claim 1, wherein the control signal transmitted by saidcontrol apparatus to the actuator apparatus of a bogie of order n of thevehicle is a function of measurements of at least one deflection α_(i)angle at an articulation center situated between adjacent ones of saidbodies of the vehicle and of the position offset h_(j) of saidarticulation center relative to the track.
 3. Apparatus according toclaim 1, wherein said actuator apparatus is force servo-controlled, saidactuator apparatus sets a force applied to at least one of the bodies ofthe vehicle from a bogie n associated with said at least one body, andthe control signal is signal_(n) for bogie n, and is a function of anintermediate parameter δ_(n) that is a function of at least onedeflection angle α_(i) and of at least one position offset h_(j) of anarticulation center relative to the track, the articulation center beingsituated between adjacent ones of said bodies of the vehicle.
 4. Acontrol apparatus for controlling an actuator apparatus implemented in asuspension system of a vehicle, the vehicle comprising bodiesarticulated together and traveling on a track, the control apparatuscomprising: means for accessing an articulated architecture of thevehicle; and means for deriving a local curvature of the track in realtime based on the articulated architecture of the vehicle, wherein theactuator apparatus is force servo-controlled and sets the force appliedto at least one of the bodies of the vehicle from a bogie n associatedwith said at least one body, the control apparatus delivers a generalcontrol signal, signal_(n), for bogie n, the signal_(n) is a function ofan intermediate parameter δ_(n) that is a function of at least onedeflection angle α_(i) and of at least one position offset h_(j) of anarticulation center relative to the track, the articulation center beingsituated between adjacent ones of said bodies of the vehicle, saidintermediate parameter δ_(n) on for n>2 is given by the followingformula: δ_(n)=α_(n)/2+α_(n+1)+(3·h _(n+1)−2·h _(n+2) −h _(n−1))/(2·d) where: d is the distance between two articulation centers in the lengthdirection; α_(n) is the deflection angle of the articulation center atthe bogie n; and h_(n) is the position offset of the articulation centerof the bogie n relative to the track; for the second (n=2) bogie of thevehicle, δ₂ is given by the following formula: δ₂=α₂/2+(2·h ₂ −h ₃ −h₁)/(2·d) and for the first (n=1) bogie of the vehicle, δ₁=0. 5.Apparatus according to claim 4, in which said general control signalsignal_(n) for bogie n is given by the following formula:signal_(n)=Gain1·(V _(TMn) −V _(TVn))+(V _(x)·δ_(n)) =Gain1·(d/dt(h_(n))+V _(x)·δ_(n)) where: V_(TMn) represents the transverse velocity ofa point M belonging to the vehicle body and located at the articulationcenter; V_(TVn) represents the transverse velocity of the pointbelonging to the track that, in the horizontal plane and when the trainis stationary, coincides with the point M; and V_(x) represents thevelocity at which the train is advancing.
 6. A method of controlling anactuator apparatus implemented in a suspension system of a vehicle, thevehicle comprising bodies articulated together and traveling on a track,the method comprising: accessing an articulated architecture of thevehicle; deriving a local curvature of the track in real time based onthe articulated architecture of the vehicle, wherein the actuatorapparatus is force servo-controlled and sets the force applied to atleast one of the bodies of the vehicle from a bogie n associated withsaid at least one body; and delivering a general control signal,signal_(n), for bogie n, wherein the signal_(n) is a function of anintermediate parameter δ_(n) that is a function of at least onedeflection angle α_(i) and of at least one position offset h_(j) of anarticulation center relative to the track, the articulation center beingsituated between adjacent ones of said bodies of the vehicle, saidintermediate parameter δ_(n) for n>2 is given by the following formula:δ_(n)=α_(n)/2+α_(n+1)+(3·h _(n+1)−2·h _(n+2) −h _(n−1))/(2·d) where: dis the distance between two articulation centers in the lengthdirection; α_(n) is the deflection angle of the articulation center atthe bogie n; and h_(n) is the position offset of the articulation centerof the bogie n relative to the track; for the second (n=2) bogie of thevehicle, δ₂ is given by the following formula: δ₂=α₂/2+(2·h ₂ −h ₃ −h₁)/(2·d) and for the first (n=1) bogie of the vehicle, δ₁=0.
 7. A methodaccording to claims 6, in which said general control signal signal_(n)for bogie n is given by the following formula: signal_(n)=Gain1·(V_(TMn) −V _(Tvn))+(V _(x)·δ_(n)) =Gain1·(d/dt(h _(n))+V _(x)·δ_(n))where: V_(TMn) represents the transverse velocity of a point M belongingto the vehicle body and located at the articulation center; V_(TVn)represents the transverse velocity of the point belonging to the trackthat, in the horizontal plane and when the train is stationary,coincides with the point M; and V_(x) represents the velocity at whichthe train is advancing.
 8. A method of controlling an actuator apparatusimplemented in a suspension system of a vehicle, the vehicle comprisingbodies articulated together and traveling on a track, the methodcomprising: accessing an articulated architecture of the vehicle;deriving a local curvature of the track in real time based on thearticulated architecture of the vehicle; and delivering a control signalto the actuator apparatus to control the suspension system of thevehicle based on the derived local curvature of the track.
 9. A methodaccording to claim 8, wherein said control signal transmitted by saidcontrol apparatus to the actuator apparatus of a bogie of order n of thevehicle is a function of measurements of at least one deflection angleα_(i) at an articulation center situated between adjacent ones of saidbodies of the vehicle and of the position offset h_(j) of saidarticulation center relative to the track.
 10. A method according toclaim 8, wherein said actuator apparatus is force servo-controlled, saidactuator apparatus sets a force applied to at least one of the bodies ofthe vehicle from a bogie n associated with said at least one body, andthe control signal is signal_(n) for bogie n, and is a function of anintermediate parameter δ_(n) that is a function of at least onedeflection angle α_(i) and of at least one position offset h_(j) of saidarticulation centers relative to the track, the articulation centerbeing situated between adjacent ones of said bodies of the vehicle.